// SPDX-License-Identifier: GPL-2.0-or-later /* * US-X2Y AUDIO * Copyright (c) 2002-2004 by Karsten Wiese * * based on * * (Tentative) USB Audio Driver for ALSA * * Main and PCM part * * Copyright (c) 2002 by Takashi Iwai <[email protected]> * * Many codes borrowed from audio.c by * Alan Cox ([email protected]) * Thomas Sailer ([email protected]) */ #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/usb.h> #include <linux/moduleparam.h> #include <sound/core.h> #include <sound/info.h> #include <sound/pcm.h> #include <sound/pcm_params.h> #include "usx2y.h" #include "usbusx2y.h" /* Default value used for nr of packs per urb. * 1 to 4 have been tested ok on uhci. * To use 3 on ohci, you'd need a patch: * look for "0000425-linux-2.6.9-rc4-mm1_ohci-hcd.patch.gz" on * "https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000425" * * 1, 2 and 4 work out of the box on ohci, if I recall correctly. * Bigger is safer operation, smaller gives lower latencies. */ #define USX2Y_NRPACKS … /* If your system works ok with this module's parameter * nrpacks set to 1, you might as well comment * this define out, and thereby produce smaller, faster code. * You'd also set USX2Y_NRPACKS to 1 then. */ #define USX2Y_NRPACKS_VARIABLE … #ifdef USX2Y_NRPACKS_VARIABLE static int nrpacks = …; /* number of packets per urb */ #define nr_of_packs() … module_param(nrpacks, int, 0444); MODULE_PARM_DESC(…) …; #else #define nr_of_packs … #endif static int usx2y_urb_capt_retire(struct snd_usx2y_substream *subs) { … } /* * prepare urb for playback data pipe * * we copy the data directly from the pcm buffer. * the current position to be copied is held in hwptr field. * since a urb can handle only a single linear buffer, if the total * transferred area overflows the buffer boundary, we cannot send * it directly from the buffer. thus the data is once copied to * a temporary buffer and urb points to that. */ static int usx2y_urb_play_prepare(struct snd_usx2y_substream *subs, struct urb *cap_urb, struct urb *urb) { … } /* * process after playback data complete * * update the current position and call callback if a period is processed. */ static void usx2y_urb_play_retire(struct snd_usx2y_substream *subs, struct urb *urb) { … } static int usx2y_urb_submit(struct snd_usx2y_substream *subs, struct urb *urb, int frame) { … } static int usx2y_usbframe_complete(struct snd_usx2y_substream *capsubs, struct snd_usx2y_substream *playbacksubs, int frame) { … } static void usx2y_clients_stop(struct usx2ydev *usx2y) { … } static void usx2y_error_urb_status(struct usx2ydev *usx2y, struct snd_usx2y_substream *subs, struct urb *urb) { … } static void i_usx2y_urb_complete(struct urb *urb) { … } static void usx2y_urbs_set_complete(struct usx2ydev *usx2y, void (*complete)(struct urb *)) { … } static void usx2y_subs_startup_finish(struct usx2ydev *usx2y) { … } static void i_usx2y_subs_startup(struct urb *urb) { … } static void usx2y_subs_prepare(struct snd_usx2y_substream *subs) { … } static void usx2y_urb_release(struct urb **urb, int free_tb) { … } /* * release a substreams urbs */ static void usx2y_urbs_release(struct snd_usx2y_substream *subs) { … } /* * initialize a substream's urbs */ static int usx2y_urbs_allocate(struct snd_usx2y_substream *subs) { … } static void usx2y_subs_startup(struct snd_usx2y_substream *subs) { … } static int usx2y_urbs_start(struct snd_usx2y_substream *subs) { … } /* * return the current pcm pointer. just return the hwptr_done value. */ static snd_pcm_uframes_t snd_usx2y_pcm_pointer(struct snd_pcm_substream *substream) { … } /* * start/stop substream */ static int snd_usx2y_pcm_trigger(struct snd_pcm_substream *substream, int cmd) { … } /* * allocate a buffer, setup samplerate * * so far we use a physically linear buffer although packetize transfer * doesn't need a continuous area. * if sg buffer is supported on the later version of alsa, we'll follow * that. */ struct s_c2 { … }; static const struct s_c2 setrate_44100[] = …; static const struct s_c2 setrate_48000[] = …; #define NOOF_SETRATE_URBS … static void i_usx2y_04int(struct urb *urb) { … } static int usx2y_rate_set(struct usx2ydev *usx2y, int rate) { … } static int usx2y_format_set(struct usx2ydev *usx2y, snd_pcm_format_t format) { … } static int snd_usx2y_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *hw_params) { … } /* * free the buffer */ static int snd_usx2y_pcm_hw_free(struct snd_pcm_substream *substream) { … } /* * prepare callback * * set format and initialize urbs */ static int snd_usx2y_pcm_prepare(struct snd_pcm_substream *substream) { … } static const struct snd_pcm_hardware snd_usx2y_2c = …; static int snd_usx2y_pcm_open(struct snd_pcm_substream *substream) { … } static int snd_usx2y_pcm_close(struct snd_pcm_substream *substream) { … } static const struct snd_pcm_ops snd_usx2y_pcm_ops = …; /* * free a usb stream instance */ static void usx2y_audio_stream_free(struct snd_usx2y_substream **usx2y_substream) { … } static void snd_usx2y_pcm_private_free(struct snd_pcm *pcm) { … } static int usx2y_audio_stream_new(struct snd_card *card, int playback_endpoint, int capture_endpoint) { … } /* * create a chip instance and set its names. */ int usx2y_audio_create(struct snd_card *card) { … }
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